Insect combatting



,action of di-nbutyl sulfone.

the invention relates to an insect com-batting agent hav- ,ing .as aneffective ingredient di-nbutyl sulfone. In a secticides and householdinsecticides.

particularly cattle, horses, etc.

piercing mouth parts which they use to penetrate the skin of the animaland thus feed on the animal.

s,ce7,091 INSEQT CtIlMBATTliNG John E. Mahan and Roy E. Stansbury,Bartlesville, @kla assignors to Phillips Petroleum Company, acorporation of Delaware 'No, Drawing. Filed Stine 3, 1958, Ser. No.739,461 1 Claim. (61.167-22) This invention relates to combatting ofinsects. In one ;of its aspects the invention relates to combattinginsects by repelling, or knocking down or killing them using a methodwith comprises subjecting the insect to the In another of its aspectsmore specific aspect ofthe invention it relates to repelling ofstableflies with di-n-butyl sulfone. This application 'is acontinuation-in-pairt of Serial No. 632,271, filed January 3, 1957, nowabandoned.

vin said application there is disclosed and claimed an insecticidalcomposition containing as an essential active ingredient di-n-butylsulfone. Also disclosed and claimed is .a method of combatting an insectwhich comprises applying to said insect a composition comprisingessentially 'di-n-butyl sulfone and an insecticide synergist.Furthermore, in said application there is disclosed and claimed a methodof combatting a fly which comprises subjecting said fly to the action ofdi-n-butyl sulfone as the sole essential combatting agent required.Other disclosures and claims. are also to be found in said application.

Insecticidal mixtures are widely used to control flies, roaches, andother insects. The field of insecticides is divided broadly into twoclassifications, agricultural in- While the primary purpose of both ofthese types of insecticides is to kill the insect, other properties arealso desirable, particularly in the household variety of insecticide.

For example, the housewife is particularly interested in obtaining aninsecticide which will quickly cause knockdown (paralysis) of flies,etc., even though'the insect being attacked does not die for some periodof time. The most widely used agent in insecticides which causesknockdown of this can be done without decreasing the rate of knockdown.

Numerous agents have been -foun-d which can be employed as replacementsfor a portion of the pyre- .,thrum in spraysforeffecting quick knockdownof insects.

Control of stable flies is a. particularly important problem on farmsand ranches. The stable fly, Stomoxys calcitrans (Linn), is a bad pestof domestic animals, Stable flies have long,

They annoy theanirnals continuously, and weaken them by loss of blood.The resulting economic loss due to stable flies is especially noticeablein the case of dairy cows,

flies, is an effective repellent for repelling stable flies.

3,06 Zeal Patented Dec. 4,1962

a rd

are bothered by large numbers of stable flies. An effective stable flyrepellent would be ofgreat'benefit to the farmer as it would bothincrease the production of milk and beef and improve the general stateof health of his animals.

We have discovered that di-n butyl sulfone is an effective insecticideand agent for producing quick knockdown and good kill of insects,particularly houseflies. Furthermore, we have also discovered thatdi-n-butyl sulfone, which is not effective as a repellent for houseit isan object of this invention to provide a method and composition forcombatting insects. It is an object of this invention toprovide aninsecticide or knockdown agent for insects, especially'useful againstflies. It is another object of this invention to provide a new knockdownagent for use as a replacement for .a portion of the pyrethrum ininsecticidal sprays.

It is a further object of this invention to provide an effectiverepellent for stable flies According to the present invention there isprovided a method for combatting insects which comprises subjecting saidinsect to the action of di-n-butyl sulfone. Also, according to theinvention there is provided an insect combatting composition whichcomprises di-n-butyl sulfone as an active ingredient.

More specifically, according to the invention di-n-butyl .sulfone isused to repel stable flies, to'knockdown insects such as flies and/or tokill insects such as flies, etc. Still more specifically, the inventionprovides a method and a composition for repelling, killing, and/orknocking down insects which can be the same or different in case of eachaction.

One skilled in the art in possession of this disclosure and havingstudied the same will understand that the compositions and rates ofapplication can be the same or different to obtain the variouscombatting results of the invention. Thus, While hereinthere aredescribed specific modes of application, carriers, components, and ratesof application in the case of each specific action primarily sought tobe accomplished, it will be clear to one skilled in the art that othermanners of application, carriers, components of compositions, and ratesof application can be employed and that since all of the conditionsdiscussed herein with respect to one primarily sought result can applyto obtain also another of the results also discussed herein.

.The insecticide additive of this invention is usually particularlyeffective when employed in an insecticidal composition in an amountwithin the range between 0.4 and 15 percent by weight, based on thetotal composition; amounts outside of this range being operative butbeing now not preferred. The insecticide of this invention is highlytoxic to insects and'can be used in insecticide compositions as the soleinsecticidal agent, or it can be used in conjunction with knowninsecticides or insecticide synergists, such as pyrethrum, pipero-nylbutoxide, 1,1,1-trichloro 2,2 bis (p-chlorophenyDethane. (DDT), 1,1,1trichloro 2,2-bis(p-methoxyphenyljethane (Methoxychlor), the gammaisomerof 1',2,3,4,5,6heXachlorocyclohexane (lindane),2,3,4,5,6,7,8,8-octachloro- 4,7-methano-3a,4,7,7a-tetrahydroindane(Chlordane) and the like. When di-n-butyl sulfone is employed alone, itis usually preferred to use a composition containing above about 3weight percent of the sulfone. When employing the insecticide of thisinvention in solution in such materials as deodorized kerosene, apractical lower limit is a concentration of 0.004 grarn/ cubiccentimeter of solvent employed. The upper limit for the concentration isdictated only by solubility in the solvent employed. When theinsecticide of this invention is employed in an insecticide containingpyrethrum, an amount of di-n-butyl sulfone as low as 0.002 gram/cubiccentimeter of solvent can be employed. In compositions containing bothpyrethrum and the insecticide of this invention, the ratio of di-n-butylsulfone to pyrethrurn usually can be within the range between :1 to140:1 by weight. A preferred ratio is from 40:1 to 80:1 on the samebasis. Since the di-n-butyl sulfone is n effective repellent for stableflies it can be compo-sited or admixed with other repellents asrepellent synergists as later set forth more specifically.

The insecticide of the present invention can be used in any of the formsin which insecticides are commonly employed. For example, thisinsecticide can be employed in insecticidal compositions which are applid as solutions, emulsions, dusts, wettable powders, aerosols and thelike. The preferred method of application of insecticidal compositionscontaining the insecticide of the present invention is in the form of aspace spray, that is, is sprayed or atomized into a confined area inwhich insects are present. Another excellent method for applying theinsecticide of this invention is to mix it into a wax and apply thewax-sulfone mixture to a surface such as tables, floors, etc.

When applying insecticides containing di-n-butyl sul tone in the form ofaerosols, the di-n-butyl sulfone can be dissolved in such solvents asnaphthas, Soltrol, kerosenes, toluene, cyclohexanone, acetone, and thelike. These solutions can then be employed in an aerosol bomb inconjunction with a propellant such as Freon and other similarnon-hazardous, compressible materials. It should also be understood thatmixtures of two or more of the above solvents can be employed.

A preferred solvent with which unusually good results are obtained isSoltrol, a hydrocarbon solvent boiling within the range 260 F. to 800F., obtained upon alkylation of an isoparaflin with an olefin in thepresence of a catalyst, for example, hydrofluoric acid. Such a processis described in U.S. Patent 2,773,920, L. H. Vautrain and E. Strunk,issued December 11, 1956. This is an isoparaflinic material possessingproperties which enhance the results obtained with the activeingredient.

The insecticide of this invention can be used in insecticidalcompositions which are employed for killing such insects as flies, ants,gnats, mosquitoes, roaches, and the like, although they are particularlyeffective when employed in compositions for killing houseflies.

When used primarily as a repellent for stable flies, di-noutyl sulfoneis usually applied to deposit 1-5O grams of this active ingredient per100 square feet. Lower or higher amounts can also be used. If less thanone gram per 100 square feet is used the period of effective repellencywill be correspondingly shortened.

The repellent of this invention can be applied to surfaces from whichstable flies are to be repelled as solutions, powders, emulsions,aerosols, creams, fogs, lotions or the like. As will be understood byone skilled in the art, solvents or carriers which can be used shouldhave no substantial detrimental effect upon the repellent activity ofdi-n-butyl sulfone or other repellents which are admixed therewith. Whenthe repellent composition is applied to livestock, it must besubstantially non-irritating and non-toxic to the animal. Examples ofsuitable carrier materials are petrolatum, acetone, deordorizedkerosene, and high-boiling isoparaflinic hydrocarbons such as areprepared by the alkylation of paraflins with olefins using hydrofluoricacid or sulfuric acid as a catalyst, as later more fully described.Solid inert carrier materials such as talc, kieselguhr, and other inertcarriers can be used in preparing dust. The repellent materials of thisinvention can also be applied in the form of emulsions, using suchemulsifying agents as alklated aryl polyether alcohols.

When the insect cornbatting material of this invention is applied in asolvent or other carrier, the concentration of the material is governedby the method of application and adjusted so as to supply a desiredamount per unit area.

When it is sought primarily to repel stable flies, it is within thescope of this invention to utilize other repellents in admixture withdi-n-butyl sulfone. Not only can other stable fly repellents be admixedwith this material, but repellents for other insects can also be used,for example, to improve the overall applicability of the repellent or toprovide an all purpose repellent effective against stable flies. Forexample, the 2,3,4,5-bis-(A -butenylene)tetrahydrofurfurals of US.2,572,577, the pyridine dicarboxylic acid diesters of U8. 2,757,120 andthe alkyl sulfoxides of Serial Number 661,584, filed May 27, 1957, canbe used in these formulations. Other materials which can be employed arethe halo-substituted sulfoxides of Serial Number 733,834, filed May 8,1958, now US. Patent No. 2,944,932, and the repellent of Serial Number742,- 738, filed lune 18, 1958, now US. Patent No. 2,952,582,2-(l-aminocyclohexyl)cyclohexanone, can be employed. it is also withinthe scope of this invention to employ pyrethrum synergists inconjunction with the repellent formulations of this invention. Forexample, piperonyl butoxide, the n-octyl sulfoxide of isosafrole,N-(Z-ethylhexyl)bicyclo[2.2.1]-5-heptene-2,3-dicarboximide can beemployed. Since it is quite common for horn flies to be associated withstable flies, it is also within the scope of this invention to add aninsecticidal ingredient to the repellent formulations, as horn flies areeasily killed by many of the known commercial ingredients. An example ofa material which can be used in the formulations of this invention tokill horn flies is Methoxychlor, 1,1,1- trichloro-2,2-bis(p-methoxyphenyl ethane.

The following examples illustrate the invention and the specificity ofthe activity of di-n-butyl sulfone as compared with other closelyrelated sulfones.

EXAMPLE I A number of runs were made in which di-n-butyl sulfone wastested alone and in admixture with other materials as a repellent forstable flies. These runs were carried out in the following manner.

Organdy bags, fabricated from organdy sheets 10 inches square, wereimpregnated with 1 gram of the candidate repellent dissolved in 6 to 7ml. of acetone and were then suspended on a line to dry. After 24 hours,the bags were drawn over the hand and exposed to several thousand hungrystable flies confined in 30-inch cubical cages. The time to the firstbite Was recorded. If no bites were received in 5 minutes, the bag waswithdrawn and inserted on the following day. If, in the firstfive-minute exposure, bites were obtained, three successive five-minuteexposures were made as described. If, however, no bites were obtained,further repetition was not made until the following day. The bags weresuspended open to aeration between trials on successive days. Generally,the flies bite in less than a minute if they bite at all. If a bite wasreceived, the number of seconds were counted to the: first, second, andthird bites. The results of these tests; are given below in Table I.

Table I Compound Seconds to first-Second-thirtd bites Dosage per 70, NB15, 12, 9 Bites received NB equals no bites.

N orrL-Thc repellents tested are coded according to the following code:

Compound N 0. Compound No. Compound N 0. Compound No. Compound No.Compound No. Compound No.

lDi-n-butyl sulfone. 22,3,4,5-bis(M-butenylene)tetrahydrofurfural.3-Di-n-propyl isocinchomeronate.

4-2- (l -aminocylohexyl) cycloh exanone. 5-3-ohloropropyl-n-octylsulfoxide. 6,n-octyl-n-propyl sulfoxid 7N-(2-ethylhexyl) bicycle EXAMPLEn A number of organic sulfones were tested for various combattingproperties by the following procedure;

An amount of the chemical to be tested as shown in Table II wasdissolved in 12 cubic centimeters of the solvent indicated. This totalsolution was sprayed into a Poet-Grady chamber in which a known numberof housefiies were contained. In each instance the total amount of thechemical was'dissolved in the solvent before spraying into the chamber.The Poet-Grady chamber is a chamber of 216 cubic feet capacity (6 x 6 x6). The number of flies knocked down, e.g., paralyzed or dead, wascounted at various time intervals, and the total number of flies thatwere dead at the end of 24- hours was counted. The results of thesetests are expressed below as Table II.

[2.2.1]-5-heptene-2,3 dicarboxyimide.

EXAMPLE In Table II Gms: Percent knockdown in X Percent chemical minutesmortality Chemical Solvent used 1 in 12 cc. after 24 solvent hoursn-Heayl ethyl sulfone 24% acetone, 16% xylene, 60% deod. kero 0.5 5 8 1113 4 Di-n-octyl sulfone 40% xylene, 60% deod. kero 0.24 14 13 15 17 17Di-n-propyl sulfone 3% cyclohexanone, 97% deod. kero 0. 36 44 51 53 48 3Di-n-amyl suli'one 40% toluene, 60% deod. kero 0. 36 3 3 5 4 4 83Tert-butyl vinyl sulione 10% cyclohexanone, 90% deod. kero 0. 18 18 1818 20 24 n-Amyl-n-propylsullone... Deod.kero 0.36 37 54 63 89 93 3 Do...do 0.24 9 19 25 26 28 6 n-Heptyl methyl sulione.-. 4% cyclohexanone, 96%deod. kero 0. 12 3 7 11 14 16 8 Di-n-butyl sulfone 16% eyolohexanone,84% deod. kero 1. 0 64 99 99 99 100 84 Do 8% cyclohexanoue, 92% deod,kero-.- 0.6 64 95 97 97 98 65 Do 6% cyclohexanone, 94% deod. kero 0.3654 93 98 98 99 48 Do. 2% cyclohexanone, 98% deod. kero 0.24 53 85 95 9698 11 Do Deod.kero 0.12 87 90 94 94 15 Do.- (lo 0.06 25 51 78 92 4 Dodo0. 03 13 14 15 27 29 3 1 Dead. kero.deodorlzed kerosene. 1 Not measured.

Table II] Table 'II of the disclosure shows that di-n-butyl sulfoneyields outstanding results. The only other sulfone, Grams db Percentlmpckdownin Percent of the group of sulfones tested, which showed even a1 11 g yl rai DY- Xmmutes mg a iy fair knockdown was n-amyl n-propylsulfone. However, 3, 3,; 3, 35 :5 as the amount of n-amyl n-propyl shownwas decreased 2 4 6 8 10 from 0.36 gram per 12 cc. to 0.24 gram per 12cc., the

o inutes d f om 0 0.0012 29 34 38 46 50 7 percent kn ckdown 1n 1(1) mdecrease h r 93 ti) 0. 024 o 0012 86 48 61 87 90 8 28. When di-n-butylsu fone was used in t e same so 0,024 0 21 33 34 43 47 7 vent as wasused for n-amyl n-propyl sulfone, the ma- 8 813 89012 fig g; 2% g terialstill exhibited a knockdown activity of 92 percent 1 0,012 9 99 100 100100 47 in 10 minutes at the rather low concentration of 0.06

gram per 12 cc. This clearly demonstrates the outstanding results of thematerial of the present invention.

1 This test was run to demonstrate that the fly colonies employed werenormal.

'2 EXAMPLE IV A small amount of a three percent (by weight) solution ofdi-n-butyl sulfone in deodorized kerosene was poured onto a laboratorybench top which had been previously coated with a heavy coat of wax. Thetable top was later washed with acetone, but it was noted that flieslanding on the surface were quickly paralyzed. Roaches were found to beaflected so quickly by crawling across the surface that they failed toget ofl the treated area before they became paralyzed. A similar effectwas noted for a ground beetle. This eflect was noted to last for two tothree days.

EXAMPLE V A run was made in which di-n-butyl sulfone was tested todetermine its repellency to house flies. Repellency to house flies wasdetermined by the Sandwich Bait method which is essentially thatdisclosed by L. D. Kilgo-re in Soap, June 1949. In accordance with thismethod, to a sheet of cardboard were applied two smooth, thin strips ofunsulfured molasses about /43" wide and 3 /2" long, leaving a margin ofat least A" all around, and a space of :at least 1'' between the strips.The prepared cardboard strips were then oven dried at 45 C. Strips ofhighly porous lens paper, 1" x 4 in dimension, were impregnated withdi-n-butyl sulfone by immersing them in an acetone solution containingone weight percent of this compound, and then allowing the strips to dryover a period of 2 to 3 hours. An impregnated strip was thensuperimposed on each strip of molasses and fastened in place by staplingit to the cardboard backing. The loose, fibrous construction of theimpregnated lens paper permits the flies to remove the molasses throughthe paper. The prepared strips were then exposed to about 150 houseflies, Musca domestica, over five days old, which had been starved forsix hours. The number of flies feeding on the molasses strips wererecorded after 5 and 15 minutes, and each 15 minutes thereafter untileither 165 minutes had elapsed or the molasses was gone. The results ofthese tests are tabulated below as a table. In this table, the word goneis used to denote the complete consumption of the molasses. Forcomparison purposes, the flies will completely consume the molasses in15 to 30 minutes, and sometimes in as short a time as 5 minutes, whenthe material is non-repellent or when no repellent ha been applied tothe lens paper.

Number of flies feeding at indicated time in minutes Repellent testedDi-n-butyl sulfone 6 3 25 Gone It is apparent from the above data thatdi-n-butyl sulfone is vIlOL efiective as a repellent for house flies. f

From the preceding example it will be noted that the discovery thatdi-n-butyl sulfone is an effective repellent for stable flies wasentirely unexpected.

Reasonable variation and modification are possible within the scope ofthe foregoing disclosure and the appended claims to the invention, theessence of which is that di-n-butyl sulfone has been discovered to be aneffective insecticide, an effective knockdown agent, a particularlyeffective combatting agent in combination with References Cited in thefile of this patent UNITED STATES PATENTS Tissol Oct. 23, 1951 LeonardJuly 31, 1956 OTHER REFERENCES Frear: A Catalogue of Insecticides andFungicides, 1947, vol. I, page 58, Chroniea Botanica Comp.

King: US. Dept. Agr. Handbook No. 69, May 1954, page 93.

I-Iartzell: Contributions From the Boyce Thompson Institute, 1949, vol.15, pages 337339.

Lindquist: US. Dept. Agr., Bulletin No. E775,-April 1949, pages 1-4 and19.

Jones: 649 0.6. 603 (8-14-51).

